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Criterion Dynamax 8 question

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135 replies to this topic

#126 tim53

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Posted 16 February 2020 - 01:27 PM

Personally, I'd fix the corrector on the DX8, or figure out how to make a new one. 

 

Leave the C8 optics in a C8. 

 

If I were inclined to make a "hybrid" either with Celestron or Criterion optics, I'd make one of my signature 9-sided plywood tubes for it.

 

post-6788-14073816558076_thumb.jpg


 

#127 deepwoods1

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Posted 16 February 2020 - 01:32 PM

That is beautiful!


 

#128 highfnum

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Posted 16 February 2020 - 01:40 PM

ok terra 

but then its something else


 

#129 Terra Nova

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Posted 16 February 2020 - 01:50 PM

ok terra 

but then its something else

Yes, that’s the idea isn’t it, to make it better than what it was. You can’t just replace the corrector and secondary that were matched to a different optical system, even if that optical system is the same basic design. That’s like expecting someone else’s glasses to work with your eyes. You both have human eyes- same basic design but different figure of lens and retina, ie. each with a different  optical defect and each set of glasses was made to a special prescription to correct it. You can’t just switch glasses and expect the same performance. You will more likely compound the problem, as you found out.


Edited by Terra Nova, 16 February 2020 - 01:51 PM.

 

#130 Chuck Hards

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Posted 16 February 2020 - 02:28 PM

I prefer the Criterion mechanicals to Celestron hands-down.  I've never really liked Meade SCTs except for the 2045.

 

I'm not commenting on my project anymore until I either get to it, or life forces me to let it go.  Just up to my armpits is real-life issues these days, sorry about that.  Not prepared to discuss it meaningfully with anyone else, I don't have the time to devote to it at present. 

 

 Ya'll have fun with it, but please don't expect a discussion from me.  I'm bowing-out of all the current DX8 discussions.


 

#131 highfnum

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Posted 16 February 2020 - 02:38 PM

terra

true simple swap does not work

in that case DAVIDG method is the only one

that stays close to original criterion design 


 

#132 Stevegeo

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Posted 16 February 2020 - 07:49 PM

Is your C8 the same length as the dyna? I never checked...

My C8 is shorter. From what can see,  but mine is an older unit.   My D8 , from the limited time I have had with it out, has better optics then the C8 ...

Maybe it's the C8.  Without another to really compare to.. say a newer unit, I cant confirm it.

 

One thing, i like the looks of the Dynamax over the C8.   And the tripod , a Golden, a firm winner for me..

 

The fork mount smooth, and rock steady on the Golden tripod... a plus . 

 

Yea I know the dynamax gets beat up for its iffy optics,  and if swapping out makes it better GO FOR IT .

I wouldnt let a few Negative  Nancy remarks stop,  you might learn something  in the process.

 

Stevegeo Area3751 observatory otisco lake ny 


 

#133 G-Tower

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Posted 16 February 2020 - 09:08 PM

A DX8 better than a C8? I thought I would never hear that!  In your case, It sounds like it would better to swap the other way, DX8 optics into C8 OTAlol.gif 


 

#134 Terra Nova

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Posted 16 February 2020 - 10:18 PM

Is your C8 the same length as the dyna? I never checked...

My C8 is shorter. From what can see,  but mine is an older unit.   My D8 , from the limited time I have had with it out, has better optics then the C8 ...

Maybe it's the C8.  Without another to really compare to.. say a newer unit, I cant confirm it.

 

One thing, i like the looks of the Dynamax over the C8.   And the tripod , a Golden, a firm winner for me..

 

The fork mount smooth, and rock steady on the Golden tripod... a plus . 

 

Yea I know the dynamax gets beat up for its iffy optics,  and if swapping out makes it better GO FOR IT .

I wouldnt let a few Negative  Nancy remarks stop,  you might learn something  in the process.

 

Stevegeo Area3751 observatory otisco lake ny 

I agree that the earlier grey and black DX8s have a much cooler ‘real scientific instrument’ look. I always said that if they weren’t really useful as telescopes, they would make great movie props! I admit that I had trouble getting used to the pumpkin orange of the C8’s when they first came out. And if you can make it better by replacing the mirrors and corrector and still retain the good looks of the tube go for it. It would sure take less time than refiguring the corrector. As long as the corrector and the primary mirror of the donor C8 would fit the DX8’s cells, I’d say go for it! All you’d need to do is shorten the DX8 tube a bit.


 

#135 G-Tower

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Posted 16 February 2020 - 11:40 PM

Shortening the tube would be easy too, a good saw should do it.


Edited by G-Tower, 16 February 2020 - 11:40 PM.

 

#136 Chuck Hards

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Posted 17 February 2020 - 08:31 AM

The original question has been answered, locking this up.


 


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